North of
Edinburgh, the East Coast railway from
London to Aberdeen had to cross the Forth and Tay rivers. The Tay was spanned first but the bridge there collapsed with a great loss of life, so the Forth Bridge was built to massive standards.
As well as the rail bridge, the modern road bridge spans the Forth at Queensferry.

Forth road and rail bridges
You might not realise the shere scale of the railway bridge until you see some people in the picture. Here, some of the local folks walk at the water's edge below the piers of the lead-in vaiduct .... yes, the bridge is high above them!

Forth Bridge
Here's the "classic" view ...

Forth Bridge
Seals abound in the Forth, and you can take boat trips out to see them on Inchcolm Island. If you don't have the time (or you're around on a day when there isn't a trip), you can see this pair in stone

South Queensferry
And, lest we forget, a rumble overhead tells us that this is a railway bridge

Forth Bridge